Dear Editor,
I am writing to commend the authors for their insightful manuscript titled "Evaluating local open-source large language models for data extraction from unstructured reports on mechanical thrombectomy in patients with ischemic stroke." (1). This study provides a rigorous evaluation of local open-source large language models (LLMs) in extracting clinical data from procedural reports, an area of increasing relevance given the rise in AI applications in healthcare.
The manuscript presents a well-structured methodology for assessing the performance of three LLMs—Mixtral, Qwen, and BioMistral—on data extraction tasks from thrombectomy reports. The choice to focus on local models, as opposed to commercial counterparts, is particularly noteworthy due to the enhanced data privacy and security benefits it entails.
Strengths of the Study:
1. Comprehensive Approach: The use of a robust human-in-the-loop (HITL) annotation strategy to establish ground truth is a commendable approach. By incorporating expert validation into the workflow, the authors not only enhance the reliability of their results but also address one of the key challenges in data extraction—ensuring the accuracy of the extracted data.
2. Clear Evaluation Metrics: The manuscript's use of precision, recall, and F1 score as metrics for evaluating model performance is appropriate and provides a detailed picture of each model's efficacy. The precision metrics, p...
Dear Editor,
I am writing to commend the authors for their insightful manuscript titled "Evaluating local open-source large language models for data extraction from unstructured reports on mechanical thrombectomy in patients with ischemic stroke." (1). This study provides a rigorous evaluation of local open-source large language models (LLMs) in extracting clinical data from procedural reports, an area of increasing relevance given the rise in AI applications in healthcare.
The manuscript presents a well-structured methodology for assessing the performance of three LLMs—Mixtral, Qwen, and BioMistral—on data extraction tasks from thrombectomy reports. The choice to focus on local models, as opposed to commercial counterparts, is particularly noteworthy due to the enhanced data privacy and security benefits it entails.
Strengths of the Study:
1. Comprehensive Approach: The use of a robust human-in-the-loop (HITL) annotation strategy to establish ground truth is a commendable approach. By incorporating expert validation into the workflow, the authors not only enhance the reliability of their results but also address one of the key challenges in data extraction—ensuring the accuracy of the extracted data.
2. Clear Evaluation Metrics: The manuscript's use of precision, recall, and F1 score as metrics for evaluating model performance is appropriate and provides a detailed picture of each model's efficacy. The precision metrics, particularly for critical data points such as NIHSS scores and first series times, underscore the potential of LLMs in streamlining clinical data extraction processes.
3. Time Efficiency: The study's findings on time savings achieved through LLM assistance, with an average reduction of 65.6% in manual extraction time, are compelling. This quantifiable benefit illustrates the practical utility of LLMs in real-world clinical settings, potentially alleviating the burden on medical professionals and accelerating the documentation process.
Areas for Further Consideration:
1. Generalizability: While the study provides valuable insights into the performance of LLMs in a specific setting and language (German), the generalizability of these findings to other languages and healthcare environments remains a consideration. Future studies could explore the performance of these models in different linguistic contexts and diverse clinical settings to broaden the applicability of the findings.
2. Model Comparison: Although the manuscript includes a comparison of model performance, additional insights into the reasons behind the variability in precision, particularly for more complex data points like medication details and occluded vessels, would be beneficial. A deeper analysis of the models' strengths and limitations in handling different types of data could guide further refinements and improvements.
3. External Validation: The use of an external dataset to evaluate model performance is a strong aspect of the study. However, incorporating validation from multiple external institutions could provide a more comprehensive assessment of model robustness and generalizability across different clinical environments.
Conclusion:
The study makes a significant contribution to the field of AI-assisted data extraction in healthcare by demonstrating the feasibility and effectiveness of local open-source LLMs in a secure and privacy-preserving manner. The findings highlight the potential of these models to support clinical documentation and research while addressing key concerns related to data privacy.
References
1. Meddeb A, Ebert P, Bressem KK, et al. Evaluating local open-source large language models for data extraction from unstructured reports on mechanical thrombectomy in patients with ischemic stroke. Journal of NeuroInterventional Surgery. Published Online First: 02 August 2024. doi: 10.1136/jnis-2024-022078
We read with great interest the corresponding letter by Dr. Sacks regarding our research article about the outcomes of mechanical thrombectomy in patients presenting with ASPECTS 0-2. We appreciate Dr. Sacks’ note regarding the acceptable clinical outcome (90-day mRS 0-3) in our study which was comparable to the outcomes reported in the large core clinical trials recently published. Regarding the mortality rate, it was reported as 4.5% in error. The correct mortality rate for patients with ASPECTS 0-2 who underwent mechanical thrombectomy is 24/58 (41.4%). We have submitted a correction to our article to reflect the correct mortality rate and updated Table 3 and Figure 2 to clarify Questions 3-5.
Dear Editor,
I am writing to express my thoughts on the article titled "Intracranial thrombus composition is associated with occlusion location and endovascular treatment outcomes: results from ITACAT multicenter study", recently published in the Journal of NeuroInterventional Surgery (1). This study provides pivotal insights into how thrombus composition affects the efficacy of mechanical thrombectomy (MT) in treating ischemic strokes, highlighting critical aspects that could influence future therapeutic strategies.
The study's retrospective analysis of 221 patients, examining thrombi retrieved during MT using hematoxylin–eosin staining and CD61 immunostaining, revealed significant associations between thrombus composition and treatment outcomes. The finding that medium distal vessel occlusions (DMVO) had higher platelet proportions than proximal large vessel occlusions (LVO) is particularly noteworthy. Specifically, middle cerebral artery (MCA) M2–M3 segment thrombi had the highest platelet content (PLTPT at 70%), whereas basilar artery thrombi had the lowest (PLTPT at 41%). These differences suggest that occlusion location can be an indicator of thrombus composition, which has crucial implications for tailoring treatment approaches.
The logistic regression analysis further strengthened the evidence by showing that lower baseline National Institutes of Health Stroke Scale (NIHSS) scores and lower PLTPT were independently associated with s...
Dear Editor,
I am writing to express my thoughts on the article titled "Intracranial thrombus composition is associated with occlusion location and endovascular treatment outcomes: results from ITACAT multicenter study", recently published in the Journal of NeuroInterventional Surgery (1). This study provides pivotal insights into how thrombus composition affects the efficacy of mechanical thrombectomy (MT) in treating ischemic strokes, highlighting critical aspects that could influence future therapeutic strategies.
The study's retrospective analysis of 221 patients, examining thrombi retrieved during MT using hematoxylin–eosin staining and CD61 immunostaining, revealed significant associations between thrombus composition and treatment outcomes. The finding that medium distal vessel occlusions (DMVO) had higher platelet proportions than proximal large vessel occlusions (LVO) is particularly noteworthy. Specifically, middle cerebral artery (MCA) M2–M3 segment thrombi had the highest platelet content (PLTPT at 70%), whereas basilar artery thrombi had the lowest (PLTPT at 41%). These differences suggest that occlusion location can be an indicator of thrombus composition, which has crucial implications for tailoring treatment approaches.
The logistic regression analysis further strengthened the evidence by showing that lower baseline National Institutes of Health Stroke Scale (NIHSS) scores and lower PLTPT were independently associated with successful first-pass effect (FPE) in MT. Moreover, achieving complete recanalization (eTICI 3) was more likely with platelet-poor thrombi (<62% PLTPT) and fewer MT passes, emphasizing the importance of thrombus composition in clinical outcomes.
The study's identification of platelets as a key factor in thrombus composition that impacts endovascular recanalization is consistent with prior research indicating the role of platelets in thrombus rigidity and resistance to fibrinolysis. The outer shell of thrombi, rich in von Willebrand factor and aggregated platelets, poses a significant challenge for fibrinolytic agents, thus impacting the success rates of recanalization.
Despite these compelling findings, the study acknowledges several limitations. The analysis primarily included patients with successful recanalization, limiting insights into unsuccessful cases. Additionally, factors like thrombus fragmentation, vessel tortuosity, and clot size were not considered, which are essential for a comprehensive understanding of MT outcomes. Future studies should incorporate these variables to provide a more holistic view of the factors influencing recanalization success.
The findings suggest that clinical trials investigating the use of selective intra-arterial platelet antagonists in combination with MT could be beneficial. Drugs such as eptifibatide and tirofiban, which prevent fibrinogen binding to platelets, may enhance the efficacy of MT by targeting the platelet-rich components of thrombi. The ongoing ACTISAVE and MOST trials, as well as meta-analyses showing favorable outcomes with intra-arterial tirofiban, underscore the potential of these adjunctive therapies.
Furthermore, the study’s insights into thrombus composition's impact on recanalization should prompt the development of next-generation thrombectomy devices tailored to the physical characteristics of clots. Comprehensive follow-up studies assessing both angiographic and clinical outcomes will be critical in validating these approaches and refining stroke treatment protocols.
In summary, the ITACAT multicenter study significantly advances our understanding of the relationship between thrombus composition, occlusion location, and MT outcomes. By highlighting the pivotal role of platelets and suggesting new therapeutic avenues, this research paves the way for more personalized and effective stroke treatments. I commend the authors for their contributions and look forward to future research that builds on these findings to further enhance stroke care.
References
1. Juega J, Requena M, Piñana C, et alIntracranial thrombus composition is associated with occlusion location and endovascular treatment outcomes: results from ITACAT multicenter studyJournal of NeuroInterventional Surgery Published Online First: 30 May 2024. doi: 10.1136/jnis-2024-021654
Dear Editor,
I am writing to address the significant findings presented in the article "Short- versus long-term Dual AntiPlatelet Therapy for Stent-Assisted treatment of CErebral aneurysm (DAPTS ACE)." This research, a randomized clinical trial aimed at unraveling the ideal duration of Dual AntiPlatelet Therapy (DAPT) after stent-assisted coil embolization (SACE) for cerebral aneurysms, raises crucial questions regarding the management of these delicate cases.
The article reports that the trial, DAPTS ACE, investigated whether extending DAPT for 12 months could effectively reduce the risk of ischemic stroke in comparison to a shorter 3-month DAPT regimen for patients who underwent SACE for cerebral aneurysms. The study, conducted in 17 hospitals in Japan, enrolled 142 patients between November 4, 2016, and January 7, 2019, and assigned them randomly to either the long-term or short-term DAPT group. The primary outcome was the occurrence of ischemic stroke events during the period of 3 to 12 months after SACE.
The results are undeniably important, as they indicate that there was no statistically significant difference in the rate of ischemic strokes between the long-term and short-term DAPT groups. In fact, ischemic stroke was a rare occurrence in both groups, and the data show that the extended duration of DAPT did not offer a significant advantage in preventing ischemic events. This is the first randomized controlled trial to tackle the duratio...
Dear Editor,
I am writing to address the significant findings presented in the article "Short- versus long-term Dual AntiPlatelet Therapy for Stent-Assisted treatment of CErebral aneurysm (DAPTS ACE)." This research, a randomized clinical trial aimed at unraveling the ideal duration of Dual AntiPlatelet Therapy (DAPT) after stent-assisted coil embolization (SACE) for cerebral aneurysms, raises crucial questions regarding the management of these delicate cases.
The article reports that the trial, DAPTS ACE, investigated whether extending DAPT for 12 months could effectively reduce the risk of ischemic stroke in comparison to a shorter 3-month DAPT regimen for patients who underwent SACE for cerebral aneurysms. The study, conducted in 17 hospitals in Japan, enrolled 142 patients between November 4, 2016, and January 7, 2019, and assigned them randomly to either the long-term or short-term DAPT group. The primary outcome was the occurrence of ischemic stroke events during the period of 3 to 12 months after SACE.
The results are undeniably important, as they indicate that there was no statistically significant difference in the rate of ischemic strokes between the long-term and short-term DAPT groups. In fact, ischemic stroke was a rare occurrence in both groups, and the data show that the extended duration of DAPT did not offer a significant advantage in preventing ischemic events. This is the first randomized controlled trial to tackle the duration of DAPT following SACE for intracranial aneurysms.
The study's findings underscore a critical point of discussion among neurointerventionalists. With the expanded use of stents for treating cerebral aneurysms, the challenge of thromboembolic complications has come to the forefront. While DAPT, combining aspirin and clopidogrel, is considered a standard regimen post-SACE, the optimal duration has remained a matter of conjecture. Various studies have explored different timeframes, from 3 months to 6 months to 9 months or more, with varying conclusions. The debate extends to the potential hemorrhagic complications associated with DAPT.
The DAPTS ACE trial brings us one step closer to addressing these uncertainties. One of the reasons cited for the lack of significant differences in outcomes is the diminishing rate of delayed thromboembolic events after SACE, largely due to advancements in stent technology. As the study indicates, the event rate was low and similar between the randomized and non-randomized cohorts, implying that the choice of enrollment may not significantly affect the results.
Moreover, the discussion delves into the importance of individualized patient therapy, particularly in terms of platelet function testing. The study highlights the significance of understanding individual variations, especially in response to clopidogrel, which is affected by genetic polymorphism. Therefore, platelet aggregation testing plays a crucial role in optimizing patient care.
While this trial offers invaluable insights, it's essential to acknowledge its limitations. The small sample size and the number of patients who achieved the primary endpoint were lower than expected. Larger studies are warranted to delve deeper into the benefits of long-term DAPT after SACE. Furthermore, the post-procedure timing of registration could have introduced some selection bias, as high-risk cases might have been avoided. However, it's noteworthy that the event rate in the non-randomized cohort was also low.
In conclusion, the DAPTS ACE trial represents a significant step in the quest to determine the ideal duration of DAPT following SACE for cerebral aneurysms. While it doesn't provide a clear verdict, it contributes significantly to the ongoing discussion in the field. The implications are not only relevant for neurointerventionalists but also for the patients who depend on these treatments. As we await further studies with larger cohorts, this research sheds light on the complexity of patient care in the realm of cerebral aneurysm treatment.
I am writing to express my appreciation for the recent publication of the multicenter study entitled "Non-ischemic cerebral enhancing (NICE) lesions after flow diversion for intracranial aneurysms: a multicenter study." The investigation sheds light on a relatively underexplored aspect of neuroendovascular procedures and provides valuable insights into the incidence, clinical presentation, and potential device-related factors associated with NICE lesions.
The study, conducted across eight centers, presents a meticulous analysis of 15 patients with NICE lesions following flow diversion. Notably, the reported incidence of 1% raises concerns given its contrast with rates observed in previous studies on various neuroendovascular procedures. This finding underscores the need for a closer examination of the potential risks and implications of flow diversion in the context of NICE lesions.
One of the notable contributions of this study is the identification of a concerning accumulation of NICE lesion cases associated with specific product lines—Pipeline devices and Derivo devices. While the study rules out the device material itself as the exclusive culprit, the hypotheses put forth regarding mechanical properties, vendor-specific catheters, and the call for further bench testing and transparent disclosure of technical details add depth to the discussion. This nuanced exploration of potential contributing factors sets the stage for more...
I am writing to express my appreciation for the recent publication of the multicenter study entitled "Non-ischemic cerebral enhancing (NICE) lesions after flow diversion for intracranial aneurysms: a multicenter study." The investigation sheds light on a relatively underexplored aspect of neuroendovascular procedures and provides valuable insights into the incidence, clinical presentation, and potential device-related factors associated with NICE lesions.
The study, conducted across eight centers, presents a meticulous analysis of 15 patients with NICE lesions following flow diversion. Notably, the reported incidence of 1% raises concerns given its contrast with rates observed in previous studies on various neuroendovascular procedures. This finding underscores the need for a closer examination of the potential risks and implications of flow diversion in the context of NICE lesions.
One of the notable contributions of this study is the identification of a concerning accumulation of NICE lesion cases associated with specific product lines—Pipeline devices and Derivo devices. While the study rules out the device material itself as the exclusive culprit, the hypotheses put forth regarding mechanical properties, vendor-specific catheters, and the call for further bench testing and transparent disclosure of technical details add depth to the discussion. This nuanced exploration of potential contributing factors sets the stage for more targeted research and a deeper understanding of the mechanisms behind NICE lesions.
The acknowledgment of study limitations, including its retrospective nature, reduced external validity, and potential selection bias due to a limited response from centers, is commendable. These limitations are crucial to consider when interpreting the findings, and the authors' emphasis on the need for a large prospective study with standardized protocols and treatment regimens is well-placed. Such an approach would not only address potential biases but also provide a more robust foundation for clinical decision-making.
The study's exploration of the diverse clinical manifestations of NICE lesions, ranging from asymptomatic findings to seizures and focal neurological deficits, adds a layer of complexity to the clinical management of these lesions. The lack of standardized recommendations for treating asymptomatic cases raises important questions about the optimal approach to care and prompts consideration of long-term immunosuppression in symptomatic cases.
In conclusion, this study significantly advances our understanding of NICE lesions following flow diversion, highlighting the need for ongoing research, transparent disclosure of technical details, and a comprehensive prospective study to validate findings and guide clinical management. I commend the authors for their contribution to the field and look forward to future research endeavors that build upon these critical insights.
Dear Editor,
I am writing to provide a thorough assessment of the recently published study titled "Cost-effectiveness of Endovascular Therapy for Acute Stroke with a Large Ischemic Region in Japan: Impact of the Alberta Stroke Program Early CT Score on Cost-effectiveness" [1]. While the study addresses important aspects of the economic implications of endovascular therapy (EVT) for acute ischemic stroke (AIS) in Japan, my analysis aims to delve deeper into specific methodological considerations and discuss the applicability of the study's findings in a broader context.
The primary focus of the study is the cost-effectiveness of EVT based on the Alberta Stroke Program Early CT Score (ASPECTS) for patients with AIS involving a large ischemic region. The conclusion that EVT is cost-effective for individuals with ASPECTS of 3–5 as determined by treating neurologists using MRI raises questions about the reliability and consistency of ASPECTS as a determinant of cost-effectiveness. Furthermore, the study acknowledges the variability in incremental costs and quality-adjusted life years (QALYs) associated with EVT in Japan compared to other countries. The higher incremental costs in Japan, attributed to the specific stroke care system and the frequent use of combined techniques and MRI, present challenges when applying these findings to healthcare systems with different cost structures and resource allocations.
The study acknowledges the variabilit...
Dear Editor,
I am writing to provide a thorough assessment of the recently published study titled "Cost-effectiveness of Endovascular Therapy for Acute Stroke with a Large Ischemic Region in Japan: Impact of the Alberta Stroke Program Early CT Score on Cost-effectiveness" [1]. While the study addresses important aspects of the economic implications of endovascular therapy (EVT) for acute ischemic stroke (AIS) in Japan, my analysis aims to delve deeper into specific methodological considerations and discuss the applicability of the study's findings in a broader context.
The primary focus of the study is the cost-effectiveness of EVT based on the Alberta Stroke Program Early CT Score (ASPECTS) for patients with AIS involving a large ischemic region. The conclusion that EVT is cost-effective for individuals with ASPECTS of 3–5 as determined by treating neurologists using MRI raises questions about the reliability and consistency of ASPECTS as a determinant of cost-effectiveness. Furthermore, the study acknowledges the variability in incremental costs and quality-adjusted life years (QALYs) associated with EVT in Japan compared to other countries. The higher incremental costs in Japan, attributed to the specific stroke care system and the frequent use of combined techniques and MRI, present challenges when applying these findings to healthcare systems with different cost structures and resource allocations.
The study acknowledges the variability in incremental costs and quality-adjusted life years (QALYs) associated with EVT in Japan compared to other countries. The higher incremental costs in Japan, attributed to the specific stroke care system and the frequent use of combined techniques and MRI, pose challenges when applying these findings to healthcare systems with different cost structures and resource allocations.
The discussion on the impact of baseline ASPECTS on cost-effectiveness draws parallels with a study conducted in the United States, suggesting that EVT for ASPECTS of 3 may not be cost-effective. However, caution is warranted when extrapolating these results to other countries due to substantial differences in patient characteristics, imaging modalities, and device strategies.
The study appropriately emphasizes the increasing importance of considering economic aspects as medical technology becomes more sophisticated and expensive, especially in aging populations. The adoption of cost-effectiveness analyses by the Central Social Insurance Medical Council in Japan reflects a growing awareness of the need to align healthcare expenditures with the value provided by medical technologies.
Nevertheless, the study's limitation in not examining the impact of various patient characteristics, such as age, time from stroke onset, stroke severity, and the involvement of eloquent areas, on the cost-effectiveness of EVT is a notable gap. Future research in this direction is crucial for understanding the nuanced factors that contribute to the economic viability of EVT in different patient cohorts.
In conclusion, while the study contributes valuable insights into the cost-effectiveness of EVT for a specific subgroup of stroke patients in Japan, its findings should be interpreted with caution when considering their broader applicability. Further research is needed to explore the generalizability of these conclusions to diverse healthcare settings and patient populations.
Reference:
1. Egashira S, Shin J, Yoshimura S, et alCost-effectiveness of endovascular therapy for acute stroke with a large ischemic region in Japan: impact of the Alberta Stroke Program Early CT Score on cost-effectivenessJournal of NeuroInterventional Surgery Published Online First: 10 December 2023. doi: 10.1136/jnis-2023-021068
Dear Editor,
I would like to commend the authors for their insightful study titled "Liquid embolic surface area as a predictor of chronic subdural hematoma resolution in middle meningeal artery embolization" [1]. The investigation into the correlation between liquid embolic surface area (LEA SA) and chronic subdural hematoma (cSDH) resolution in the context of middle meningeal artery embolization (MMAE) presents valuable contributions to the field. The authors employed a meticulous approach, retrospectively collecting data from 74 patients who underwent first-line MMAE with ethylene vinyl alcohol (EVOH) and utilizing 3D segmentation to quantify LEA SA. The observed correlation between greater LEA SA and enhanced cSDH resolution rates at 3 months and 6 months post-embolization is a noteworthy contribution to the field.
The study's strength lies in its unique focus on a patient group undergoing first-line MMAE for cSDH, a subset that has been relatively underrepresented in the existing literature. The authors rightly acknowledge the potential selection bias in this group, considering patients with greater midline shift or poor neurologic exams might be directed immediately to surgical treatment. Nonetheless, the results support the utilization of upfront MMAE in patients with riskier surgical profiles due to comorbidities or borderline radiographic and clinical features.
However, it is essential to scrutinize the limitations outlined by the a...
Dear Editor,
I would like to commend the authors for their insightful study titled "Liquid embolic surface area as a predictor of chronic subdural hematoma resolution in middle meningeal artery embolization" [1]. The investigation into the correlation between liquid embolic surface area (LEA SA) and chronic subdural hematoma (cSDH) resolution in the context of middle meningeal artery embolization (MMAE) presents valuable contributions to the field. The authors employed a meticulous approach, retrospectively collecting data from 74 patients who underwent first-line MMAE with ethylene vinyl alcohol (EVOH) and utilizing 3D segmentation to quantify LEA SA. The observed correlation between greater LEA SA and enhanced cSDH resolution rates at 3 months and 6 months post-embolization is a noteworthy contribution to the field.
The study's strength lies in its unique focus on a patient group undergoing first-line MMAE for cSDH, a subset that has been relatively underrepresented in the existing literature. The authors rightly acknowledge the potential selection bias in this group, considering patients with greater midline shift or poor neurologic exams might be directed immediately to surgical treatment. Nonetheless, the results support the utilization of upfront MMAE in patients with riskier surgical profiles due to comorbidities or borderline radiographic and clinical features.
However, it is essential to scrutinize the limitations outlined by the authors and contemplate potential strategies for addressing these constraints in future work. The retrospective nature of the study introduces inherent biases and limitations associated with patient selection. The inclusion of patients who underwent MMAE as a first-line therapy may skew the results, as this subgroup may not have as sizable hematomas as those managed with surgery initially. To overcome this limitation, future studies should be designed in a prospective manner with clinical equipoise, allowing for a more comprehensive and unbiased comparison between MMAE and surgical management. This would help in better understanding the relative efficacy of MMAE in different patient populations.
The study's focus on radiographic data is another limitation, as it did not include crucial clinical datapoints such as hematologic laboratory values, corticosteroid usage, antiplatelet or anticoagulation therapy, the etiology of cSDH, and comorbidities. Future research endeavors could benefit from incorporating a more comprehensive set of clinical parameters to provide a holistic understanding of the factors influencing cSDH resolution.
A notable limitation highlighted by the authors is the absence of pre-embolization DynaCT scans in the segmentation process, leading to potential artifacts from overlying bone. To enhance the accuracy of LEA SA calculation and verification, future studies should consider including both pre- and post-DynaCT scans. This approach would mitigate the impact of artifacts and provide a clearer understanding of LEA penetration into the microvasculature of the subdural membranes.
The authors' acknowledgment of these limitations demonstrates their commitment to transparency and scientific rigor. As we move forward, the field could benefit from collaborative efforts to standardize imaging protocols, ensuring consistency and comparability across studies. Additionally, exploring advanced imaging or reconstruction methods, such as dual-energy CT or secondary reconstructions with a smaller volume of interest, could further enhance the precision of LEA SA measurements.
In conclusion, while celebrating the significant insights derived from this study, it is crucial to recognize the outlined limitations as opportunities for improvement. Addressing these limitations in future research endeavors will not only strengthen the robustness of findings but also contribute to advancing the understanding of the intricate interplay between LEA SA and cSDH resolution in the context of MMAE.
Reference
1. John K, Syed S, Kaestner T, et alLiquid embolic surface area as a predictor of chronic subdural hematoma resolution in middle meningeal artery embolizationJournal of NeuroInterventional Surgery Published Online First: 28 November 2023.
I am writing to discuss the recent article titled "Incidence of intracranial hemorrhagic complications after anterior circulation endovascular thrombectomy in relation to occlusion site: a nationwide observational register study" (1). This study provides valuable insights into intracranial hemorrhage (ICH) as a potential complication of endovascular thrombectomy (EVT) in patients with anterior circulation vessel occlusion stroke. The authors conducted a comprehensive analysis, considering different occlusion sites and their associations with the incidence and severity of ICH, specifically symptomatic (sICH) and non-symptomatic (non-sICH) cases. While the study presents crucial findings, it is essential to discuss its implications and limitations.
The study's key finding of a 4.5% incidence of sICH after EVT for anterior circulation vessel occlusion stroke is consistent with previous research in this area. The recognition of differences in the frequency and severity of ICH across occlusion sites, particularly in the internal carotid artery (ICA), middle cerebral artery's first segment (M1), and the M2 and beyond, is a significant contribution to our understanding of EVT outcomes. The study suggests that ICA occlusions, despite their lower overall hemorrhage frequency, tend to result in more severe ICH, including intraventricular hemorrhages and space-occupying intracerebral hemorrhages. This observation aligns with prior stud...
I am writing to discuss the recent article titled "Incidence of intracranial hemorrhagic complications after anterior circulation endovascular thrombectomy in relation to occlusion site: a nationwide observational register study" (1). This study provides valuable insights into intracranial hemorrhage (ICH) as a potential complication of endovascular thrombectomy (EVT) in patients with anterior circulation vessel occlusion stroke. The authors conducted a comprehensive analysis, considering different occlusion sites and their associations with the incidence and severity of ICH, specifically symptomatic (sICH) and non-symptomatic (non-sICH) cases. While the study presents crucial findings, it is essential to discuss its implications and limitations.
The study's key finding of a 4.5% incidence of sICH after EVT for anterior circulation vessel occlusion stroke is consistent with previous research in this area. The recognition of differences in the frequency and severity of ICH across occlusion sites, particularly in the internal carotid artery (ICA), middle cerebral artery's first segment (M1), and the M2 and beyond, is a significant contribution to our understanding of EVT outcomes. The study suggests that ICA occlusions, despite their lower overall hemorrhage frequency, tend to result in more severe ICH, including intraventricular hemorrhages and space-occupying intracerebral hemorrhages. This observation aligns with prior studies and may be attributed to various factors, including the larger affected brain area and differences in vascular supply.
The study emphasizes the complexity of managing blood pressure following EVT, as it plays a critical role in achieving optimal reperfusion while minimizing the risk of adverse events, particularly in cases involving proximal vessel occlusions. Furthermore, the authors shed light on the administration of antithrombotic medication during EVT for ICA occlusions and its potential impact on sICH. This is particularly relevant given the rising concern regarding the risk of hemorrhagic complications associated with procedural antithrombotic medication.
The findings regarding EVT for occlusions in the M2 and beyond are promising, with a relatively lower incidence of sICH. The study suggests room for improvement in revascularization efficacy for these distal vessels. This is a significant consideration as it indicates that EVT should not be discouraged for the treatment of more distal vascular domains within the middle cerebral artery territory.
However, it is crucial to acknowledge the study's limitations. The definition of sICH in this study differs from the Heidelberg Bleeding Classification, which may affect the frequency of sICH cases. The categorization of sICH and δ-NIHSS was not complete in the registry, which might result in an underestimation of sICH. Additionally, the use of a modified ASPECT score for the estimation of the affected brain area is subject to inherent limitations, and further research may benefit from a more precise approach.
In conclusion, this study provides valuable insights into the incidence and severity of ICH following EVT for anterior circulation vessel occlusion stroke, with a particular focus on different occlusion sites. The findings have important implications for clinical practice, especially in managing blood pressure and antithrombotic medication during and after EVT. While the study's limitations should be considered, its contributions to our understanding of EVT outcomes are noteworthy and may guide future research in this area.
References:
1. Hall E, Ullberg T, Andsberg G, et alIncidence of intracranial hemorrhagic complications after anterior circulation endovascular thrombectomy in relation to occlusion site: a nationwide observational register studyJournal of NeuroInterventional Surgery Published Online First: 05 October 2023. doi: 10.1136/jnis-2023-020768
We have read with great interest the article entitled “Efficacy and mid-term outcome of middle meningeal artery embolization with or without burr hole evacuation for chronic subdural hematoma compared with burr hole evacuation alone” by Onyinzo, C., et al, published in Journal of NeuroInterventional Surgery (2021).
The article has compared the Surgical and Endovascular management of (CSDH) in the elderly population who are at high risk to developing (CSDH) due to their co-morbidities and the use of anti-thrombotic agents.
It is noted that the anti-thrombotic agents were stopped to both management arms. Upfront Middle meningeal artery embolization without stopping the anti-thrombotics, might be a strategy to mitigate the risk of cardio-embolic events.
In regards to the evaluation of the patients outcome, clinical parameters did not include motor assessment, which is a significant factor to favor a rapid surgical evacuation in these delicate patients.
As to the radiological follow up, cured (CSDH) were defined in the article with a thickness less than 10 mm. This is debatable as there are a lot of variations exists for this population in regards to brain volume and brain elasticity.
Finally, we would like to point out the timing of the follow up was not defines for all patients. This need to be harmonized better to a well-defined follow up timeline. Joyce, MD, et al,2 a suggested a time frame of 6 weeks after the treatment...
We have read with great interest the article entitled “Efficacy and mid-term outcome of middle meningeal artery embolization with or without burr hole evacuation for chronic subdural hematoma compared with burr hole evacuation alone” by Onyinzo, C., et al, published in Journal of NeuroInterventional Surgery (2021).
The article has compared the Surgical and Endovascular management of (CSDH) in the elderly population who are at high risk to developing (CSDH) due to their co-morbidities and the use of anti-thrombotic agents.
It is noted that the anti-thrombotic agents were stopped to both management arms. Upfront Middle meningeal artery embolization without stopping the anti-thrombotics, might be a strategy to mitigate the risk of cardio-embolic events.
In regards to the evaluation of the patients outcome, clinical parameters did not include motor assessment, which is a significant factor to favor a rapid surgical evacuation in these delicate patients.
As to the radiological follow up, cured (CSDH) were defined in the article with a thickness less than 10 mm. This is debatable as there are a lot of variations exists for this population in regards to brain volume and brain elasticity.
Finally, we would like to point out the timing of the follow up was not defines for all patients. This need to be harmonized better to a well-defined follow up timeline. Joyce, MD, et al,2 a suggested a time frame of 6 weeks after the treatment and then at 90 days
We believe these points will bridge the findings of the authors to the real-world practice, by accounting for more clinical and radiological parameters to consolidate recommendations of practice.
References
Catapano, J. S., Nguyen, C., Wakim, A., Albuquerque, F., & Ducruet, A. (2020). Joshua S. Catapano. Frontiers in Neurology , 11. https://doi.org/10.3389/fneur.2020.557233
Joyce, E., Bounajem, M. T., Scoville, J., Thomas, A. J., Ogilvy, C. S., Riina, H. A., Tanweer, O., Levy, E. I., Spiotta, A. M., Gross, B. A., Jankowitz, B. T., Cawley, C. M., Khalessi, A. A., Pandey, A. S., Ringer, A. J., Hanel, R., Ortiz, R. A., Langer, D., Levitt, M. R., … Grandhi, R. (2020). Middle meningeal artery embolization treatment of nonacute subdural hematomas in the elderly: a multiinstitutional experience of 151 cases. Neurosurgical Focus, 49(4). https://doi.org/10.3171/2020.7.focus20518
Jumah, F., Osama, M., Islim, A. I., Jumah, A., Patra, D. P., Kosty, J., Narayan, V., Nanda, A., Gupta, G., & Dossani, R. H. (2020). Efficacy and safety of middle meningeal artery embolization in the management of refractory or chronic subdural hematomas: a systematic review and meta-analysis. Acta Neurochirurgica, 162(3), 499–507. https://doi.org/10.1007/s00701-019-04161-3
Srivatsan, A., Mohanty, A., Nascimento, F. A., Hafeez, M. U., Srinivasan, V. M., Thomas, A., Chen, S. R., Johnson, J. N., & Kan, P. (2019). Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: Meta-Analysis and Systematic Review. World Neurosurgery, 122, 613–619. https://doi.org/10.1016/j.wneu.2018.11.167
I read with interest the paper by Pierot et al [1]. They conducted a prospective study to examine factors of delayed thromboembolic events in 335 patients after coiling of unruptured intracranial aneurysms. The number of delayed TEEs was 8. The adjusted odds ratios (95% confidence intervals) of autosomal dominant polycystic kidney disease and post-procedure aneurysm remnant at procedure completion for delayed TEEs were 27.3 (3.9 to 190.2) and 9.9 (1.0 to 51.3), respectively. They understand the lack of statistical power in the multivariate analysis and did not intend to examine the causal association. I present a comment regarding the number of events in logistic regression analysis.
The limitation in the total number of events for logistic regression analysis was simulated to improve statistical power [2]. In addition, Peduzzi et al. evaluated the effect of the number of events per variable (EPV) on the outcome in logistic regression analysis [3], concluding that the number of EPV less than 10 has some problems for the prediction of dependent variable. There is an opinion that EPV value less than 10 is also acceptable to evaluate the association by logistic regression analysis [4]. Pierot et al. observed 8 events, which was not appropriate for multivariate analysis even for examining the association instead of prediction in a prospective study. I think that wide ranges of 95% confidence intervals may reflect unstable estimates in a logistic regr...
I read with interest the paper by Pierot et al [1]. They conducted a prospective study to examine factors of delayed thromboembolic events in 335 patients after coiling of unruptured intracranial aneurysms. The number of delayed TEEs was 8. The adjusted odds ratios (95% confidence intervals) of autosomal dominant polycystic kidney disease and post-procedure aneurysm remnant at procedure completion for delayed TEEs were 27.3 (3.9 to 190.2) and 9.9 (1.0 to 51.3), respectively. They understand the lack of statistical power in the multivariate analysis and did not intend to examine the causal association. I present a comment regarding the number of events in logistic regression analysis.
The limitation in the total number of events for logistic regression analysis was simulated to improve statistical power [2]. In addition, Peduzzi et al. evaluated the effect of the number of events per variable (EPV) on the outcome in logistic regression analysis [3], concluding that the number of EPV less than 10 has some problems for the prediction of dependent variable. There is an opinion that EPV value less than 10 is also acceptable to evaluate the association by logistic regression analysis [4]. Pierot et al. observed 8 events, which was not appropriate for multivariate analysis even for examining the association instead of prediction in a prospective study. I think that wide ranges of 95% confidence intervals may reflect unstable estimates in a logistic regression analysis.
Their study is important for clarifying risk factors of delayed thromboembolic events even though the prevalence of adverse effect is low. I recommend that EPV should be kept higher by making larger sample sizes for keeping stable risk estimation.
REFERENCES
[1] Pierot L, Barbe C, Herbreteau D, et al. Delayed thromboembolic events after coiling of unruptured intracranial aneurysms in a prospective cohort of 335 patients. J Neurointerv Surg 2021;13(6):534-540.
[2] Novikov I, Fund N, Freedman LS. A modified approach to estimating sample size for simple logistic regression with one continuous covariate. Stat Med 2010;29(1):97-107.
[3] Peduzzi P, Concato J, Kemper E, et al. A simulation study of the number of events per variable in logistic regression analysis. J Clin Epidemiol 1996;49(12):1373-1379.
[4] Vittinghoff E, McCulloch CE. Relaxing the rule of ten events per variable in logistic and Cox regression. Am J Epidemiol 2007;165(6):710-718.
Dear Editor,
Show MoreI am writing to commend the authors for their insightful manuscript titled "Evaluating local open-source large language models for data extraction from unstructured reports on mechanical thrombectomy in patients with ischemic stroke." (1). This study provides a rigorous evaluation of local open-source large language models (LLMs) in extracting clinical data from procedural reports, an area of increasing relevance given the rise in AI applications in healthcare.
The manuscript presents a well-structured methodology for assessing the performance of three LLMs—Mixtral, Qwen, and BioMistral—on data extraction tasks from thrombectomy reports. The choice to focus on local models, as opposed to commercial counterparts, is particularly noteworthy due to the enhanced data privacy and security benefits it entails.
Strengths of the Study:
1. Comprehensive Approach: The use of a robust human-in-the-loop (HITL) annotation strategy to establish ground truth is a commendable approach. By incorporating expert validation into the workflow, the authors not only enhance the reliability of their results but also address one of the key challenges in data extraction—ensuring the accuracy of the extracted data.
2. Clear Evaluation Metrics: The manuscript's use of precision, recall, and F1 score as metrics for evaluating model performance is appropriate and provides a detailed picture of each model's efficacy. The precision metrics, p...
We read with great interest the corresponding letter by Dr. Sacks regarding our research article about the outcomes of mechanical thrombectomy in patients presenting with ASPECTS 0-2. We appreciate Dr. Sacks’ note regarding the acceptable clinical outcome (90-day mRS 0-3) in our study which was comparable to the outcomes reported in the large core clinical trials recently published. Regarding the mortality rate, it was reported as 4.5% in error. The correct mortality rate for patients with ASPECTS 0-2 who underwent mechanical thrombectomy is 24/58 (41.4%). We have submitted a correction to our article to reflect the correct mortality rate and updated Table 3 and Figure 2 to clarify Questions 3-5.
Dear Editor,
Show MoreI am writing to express my thoughts on the article titled "Intracranial thrombus composition is associated with occlusion location and endovascular treatment outcomes: results from ITACAT multicenter study", recently published in the Journal of NeuroInterventional Surgery (1). This study provides pivotal insights into how thrombus composition affects the efficacy of mechanical thrombectomy (MT) in treating ischemic strokes, highlighting critical aspects that could influence future therapeutic strategies.
The study's retrospective analysis of 221 patients, examining thrombi retrieved during MT using hematoxylin–eosin staining and CD61 immunostaining, revealed significant associations between thrombus composition and treatment outcomes. The finding that medium distal vessel occlusions (DMVO) had higher platelet proportions than proximal large vessel occlusions (LVO) is particularly noteworthy. Specifically, middle cerebral artery (MCA) M2–M3 segment thrombi had the highest platelet content (PLTPT at 70%), whereas basilar artery thrombi had the lowest (PLTPT at 41%). These differences suggest that occlusion location can be an indicator of thrombus composition, which has crucial implications for tailoring treatment approaches.
The logistic regression analysis further strengthened the evidence by showing that lower baseline National Institutes of Health Stroke Scale (NIHSS) scores and lower PLTPT were independently associated with s...
Dear Editor,
Show MoreI am writing to address the significant findings presented in the article "Short- versus long-term Dual AntiPlatelet Therapy for Stent-Assisted treatment of CErebral aneurysm (DAPTS ACE)." This research, a randomized clinical trial aimed at unraveling the ideal duration of Dual AntiPlatelet Therapy (DAPT) after stent-assisted coil embolization (SACE) for cerebral aneurysms, raises crucial questions regarding the management of these delicate cases.
The article reports that the trial, DAPTS ACE, investigated whether extending DAPT for 12 months could effectively reduce the risk of ischemic stroke in comparison to a shorter 3-month DAPT regimen for patients who underwent SACE for cerebral aneurysms. The study, conducted in 17 hospitals in Japan, enrolled 142 patients between November 4, 2016, and January 7, 2019, and assigned them randomly to either the long-term or short-term DAPT group. The primary outcome was the occurrence of ischemic stroke events during the period of 3 to 12 months after SACE.
The results are undeniably important, as they indicate that there was no statistically significant difference in the rate of ischemic strokes between the long-term and short-term DAPT groups. In fact, ischemic stroke was a rare occurrence in both groups, and the data show that the extended duration of DAPT did not offer a significant advantage in preventing ischemic events. This is the first randomized controlled trial to tackle the duratio...
Dear Editor,
I am writing to express my appreciation for the recent publication of the multicenter study entitled "Non-ischemic cerebral enhancing (NICE) lesions after flow diversion for intracranial aneurysms: a multicenter study." The investigation sheds light on a relatively underexplored aspect of neuroendovascular procedures and provides valuable insights into the incidence, clinical presentation, and potential device-related factors associated with NICE lesions.
The study, conducted across eight centers, presents a meticulous analysis of 15 patients with NICE lesions following flow diversion. Notably, the reported incidence of 1% raises concerns given its contrast with rates observed in previous studies on various neuroendovascular procedures. This finding underscores the need for a closer examination of the potential risks and implications of flow diversion in the context of NICE lesions.
One of the notable contributions of this study is the identification of a concerning accumulation of NICE lesion cases associated with specific product lines—Pipeline devices and Derivo devices. While the study rules out the device material itself as the exclusive culprit, the hypotheses put forth regarding mechanical properties, vendor-specific catheters, and the call for further bench testing and transparent disclosure of technical details add depth to the discussion. This nuanced exploration of potential contributing factors sets the stage for more...
Show MoreDear Editor,
Show MoreI am writing to provide a thorough assessment of the recently published study titled "Cost-effectiveness of Endovascular Therapy for Acute Stroke with a Large Ischemic Region in Japan: Impact of the Alberta Stroke Program Early CT Score on Cost-effectiveness" [1]. While the study addresses important aspects of the economic implications of endovascular therapy (EVT) for acute ischemic stroke (AIS) in Japan, my analysis aims to delve deeper into specific methodological considerations and discuss the applicability of the study's findings in a broader context.
The primary focus of the study is the cost-effectiveness of EVT based on the Alberta Stroke Program Early CT Score (ASPECTS) for patients with AIS involving a large ischemic region. The conclusion that EVT is cost-effective for individuals with ASPECTS of 3–5 as determined by treating neurologists using MRI raises questions about the reliability and consistency of ASPECTS as a determinant of cost-effectiveness. Furthermore, the study acknowledges the variability in incremental costs and quality-adjusted life years (QALYs) associated with EVT in Japan compared to other countries. The higher incremental costs in Japan, attributed to the specific stroke care system and the frequent use of combined techniques and MRI, present challenges when applying these findings to healthcare systems with different cost structures and resource allocations.
The study acknowledges the variabilit...
Dear Editor,
Show MoreI would like to commend the authors for their insightful study titled "Liquid embolic surface area as a predictor of chronic subdural hematoma resolution in middle meningeal artery embolization" [1]. The investigation into the correlation between liquid embolic surface area (LEA SA) and chronic subdural hematoma (cSDH) resolution in the context of middle meningeal artery embolization (MMAE) presents valuable contributions to the field. The authors employed a meticulous approach, retrospectively collecting data from 74 patients who underwent first-line MMAE with ethylene vinyl alcohol (EVOH) and utilizing 3D segmentation to quantify LEA SA. The observed correlation between greater LEA SA and enhanced cSDH resolution rates at 3 months and 6 months post-embolization is a noteworthy contribution to the field.
The study's strength lies in its unique focus on a patient group undergoing first-line MMAE for cSDH, a subset that has been relatively underrepresented in the existing literature. The authors rightly acknowledge the potential selection bias in this group, considering patients with greater midline shift or poor neurologic exams might be directed immediately to surgical treatment. Nonetheless, the results support the utilization of upfront MMAE in patients with riskier surgical profiles due to comorbidities or borderline radiographic and clinical features.
However, it is essential to scrutinize the limitations outlined by the a...
To the Editor,
I am writing to discuss the recent article titled "Incidence of intracranial hemorrhagic complications after anterior circulation endovascular thrombectomy in relation to occlusion site: a nationwide observational register study" (1). This study provides valuable insights into intracranial hemorrhage (ICH) as a potential complication of endovascular thrombectomy (EVT) in patients with anterior circulation vessel occlusion stroke. The authors conducted a comprehensive analysis, considering different occlusion sites and their associations with the incidence and severity of ICH, specifically symptomatic (sICH) and non-symptomatic (non-sICH) cases. While the study presents crucial findings, it is essential to discuss its implications and limitations.
The study's key finding of a 4.5% incidence of sICH after EVT for anterior circulation vessel occlusion stroke is consistent with previous research in this area. The recognition of differences in the frequency and severity of ICH across occlusion sites, particularly in the internal carotid artery (ICA), middle cerebral artery's first segment (M1), and the M2 and beyond, is a significant contribution to our understanding of EVT outcomes. The study suggests that ICA occlusions, despite their lower overall hemorrhage frequency, tend to result in more severe ICH, including intraventricular hemorrhages and space-occupying intracerebral hemorrhages. This observation aligns with prior stud...
Show MoreDear Editor,
We have read with great interest the article entitled “Efficacy and mid-term outcome of middle meningeal artery embolization with or without burr hole evacuation for chronic subdural hematoma compared with burr hole evacuation alone” by Onyinzo, C., et al, published in Journal of NeuroInterventional Surgery (2021).
The article has compared the Surgical and Endovascular management of (CSDH) in the elderly population who are at high risk to developing (CSDH) due to their co-morbidities and the use of anti-thrombotic agents.
Show MoreIt is noted that the anti-thrombotic agents were stopped to both management arms. Upfront Middle meningeal artery embolization without stopping the anti-thrombotics, might be a strategy to mitigate the risk of cardio-embolic events.
In regards to the evaluation of the patients outcome, clinical parameters did not include motor assessment, which is a significant factor to favor a rapid surgical evacuation in these delicate patients.
As to the radiological follow up, cured (CSDH) were defined in the article with a thickness less than 10 mm. This is debatable as there are a lot of variations exists for this population in regards to brain volume and brain elasticity.
Finally, we would like to point out the timing of the follow up was not defines for all patients. This need to be harmonized better to a well-defined follow up timeline. Joyce, MD, et al,2 a suggested a time frame of 6 weeks after the treatment...
Dear Editor,
I read with interest the paper by Pierot et al [1]. They conducted a prospective study to examine factors of delayed thromboembolic events in 335 patients after coiling of unruptured intracranial aneurysms. The number of delayed TEEs was 8. The adjusted odds ratios (95% confidence intervals) of autosomal dominant polycystic kidney disease and post-procedure aneurysm remnant at procedure completion for delayed TEEs were 27.3 (3.9 to 190.2) and 9.9 (1.0 to 51.3), respectively. They understand the lack of statistical power in the multivariate analysis and did not intend to examine the causal association. I present a comment regarding the number of events in logistic regression analysis.
The limitation in the total number of events for logistic regression analysis was simulated to improve statistical power [2]. In addition, Peduzzi et al. evaluated the effect of the number of events per variable (EPV) on the outcome in logistic regression analysis [3], concluding that the number of EPV less than 10 has some problems for the prediction of dependent variable. There is an opinion that EPV value less than 10 is also acceptable to evaluate the association by logistic regression analysis [4]. Pierot et al. observed 8 events, which was not appropriate for multivariate analysis even for examining the association instead of prediction in a prospective study. I think that wide ranges of 95% confidence intervals may reflect unstable estimates in a logistic regr...
Show MorePages